As far as Sodom and Gomorrah is concerned; even though I tend to agree with Ron Wyatt on this assessment, I am not aware of definitive proof that they were located where the Dead Sea is now.
It just occurred to me that where they were may be impossible to determine, on the basis that there may be nothing at all left to find.
When describing the fire from heaven at Mount Carmel the Bible says that even the stones were consumed.
"Then the fire of the LORD fell, and consumed the burnt sacrifice, and the wood, and the stones, and the dust, and licked up the water that was in the trench." (1 Kings 18:38)
The Bible then further compares the ultimate destruction of all the wicked to what happened to Sodom and Gomorrah, pointing out that the cities were turned into ashes.
"And turning the cities of Sodom and Gomorrha into ashes condemned them with an overthrow, making them an ensample unto those that after should live ungodly;" (2 Peter 2:6)